1. Field of the Invention
The present invention relates to welding, and, in particular, to welding complicated, difficult-to-weld components made of heat treatable steels for receivers of machine guns.
2. Discussion of Background
Metal components can be made by casting, machining, welding, forging or a combination of two or more of these processes. The choice of process depends on the component and cost. If the component is composed of parts made of different materials, welding those different parts together is the desirable choice (assuming that the parts are to be permanently fastened together). However, when the component is "complicated" to weld, that is, it is (1) made of a relatively large number of components, (2) asymmetric, (3) made of incompatible or heat treatable metals, (4) made of metals of different thicknesses, and (5) required to meet close tolerances, the difficulties in manufacturing can be almost insurmountable, at least at a cost that the purchaser will accept.
The goal of the manufacturing process is to make components that meet quality and dimensional requirements with minimal rejects at reasonable cost. Certain aspects of manufacturing are known to produce better quality welded components: making parts that meet fine tolerances; assembling the parts in a jig or fixture that holds each part in the correct relative position; using robotic welders in conjunction with a referenced work surface to assure a repeatable, controllable welding operation; checking the tolerance of finished parts; carefully controlling heat deposition; cleaning the parts and fixtures frequently. These are well known.
Manufacturing complicated components such as receivers for machine guns used in combat is especially important. The conditions of combat are hard on weaponry, especially a machine gun, yet the weapon must remain ready to fire. Also, it is important to contain the cost of a weapon that is used in large numbers. Being able to weld the parts of a receiver together effectively will keep the cost of the receiver lower than other manufacturing alternatives. Consequently, there remains a need for a welding process for complicated components that can yield a finished work product meeting close tolerances.